1. Field of the Invention
The present invention relates to a method of forming a nitrogen-doped porous graphene envelope, and more particularly to a method of forming a nitrogen-doped porous graphene envelope, the method including dissolving a nitrogen precursor in an organic precursor (a carbon precursor) and then vaporizing the resulting precursor to thus simultaneously synthesize the graphene envelope and perform nitrogen doping in a single step.
2. Description of the Related Art
Ammonia (gas or liquid) or pyridine (liquid) including nitrogen is typically used as a gas or liquid precursor in order to dope carbonized substances with nitrogen. Typically, after carbonized substances, such as carbon nanotubes, graphite, or graphene, are synthesized, nitrogen compounds are added and high-temperature and high-pressure conditions are applied to perform nitrification (nitrogen doping). For example, Applied Surface Science 257 (2011) 9193-9198 by Geng et al. discloses that graphene, which is obtained by treating graphite oxide slurry at 1050° C., is treated at 900° C. in order to dope the surface of graphene with nitrogen. Thin Solid Films 520 (2012) 6850-6855 by Zhang, et al. discloses that a solution, which includes ethanol (70%) and ammonia (30%) mixed therein, is heated to 800° C. or more in order to synthesize nitrogen-doped graphene. As another example, Chemical Engineering Journal 156 (2010) 404-410 by Chen, et al. discloses that N2 microwave plasma is applied with a frequency of 2.45 GHz at 50 to 1000 W to perform treatment under a 60 to 90 Torr condition to thus dope the surface of CNT with nitrogen.
The present invention provides a simple and economical process of simultaneously synthesizing graphene and performing nitrogen doping in a single step without incurring additional costs, instead of high-temperature, high-pressure, and high-cost processes performed in respective stages after graphene is produced.